/* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
 */

#include   "md5-radius.h"

md5_calc (output, input, inlen)
unsigned char  *output;
unsigned char  *input;          /* input block */
unsigned int    inlen;          /* length of input block */
{
        MD5_CTX         context;

        MD5Init (&context);
        MD5Update (&context, input, inlen);
        MD5Final (output, &context);
}


/* MD5 basic transformation. Transforms state based on block.
 */
static void 
MD5Transform (state, block)
UINT4           state[4];
unsigned char   block[64];
{
        UINT4           a = state[0],
                        b = state[1],
                        c = state[2],
                        d = state[3],
                        x[16];

        Decode (x, block, 64);

        /* Round 1 */
        FF (a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
        FF (d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
        FF (c, d, a, b, x[2], S13, 0x242070db); /* 3 */
        FF (b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
        FF (a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
        FF (d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
        FF (c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
        FF (b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
        FF (a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
        FF (d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
        FF (c, d, a, b, x[10], S13, 0xffff5bb1);        /* 11 */
        FF (b, c, d, a, x[11], S14, 0x895cd7be);        /* 12 */
        FF (a, b, c, d, x[12], S11, 0x6b901122);        /* 13 */
        FF (d, a, b, c, x[13], S12, 0xfd987193);        /* 14 */
        FF (c, d, a, b, x[14], S13, 0xa679438e);        /* 15 */
        FF (b, c, d, a, x[15], S14, 0x49b40821);        /* 16 */

        /* Round 2 */
        GG (a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
        GG (d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
        GG (c, d, a, b, x[11], S23, 0x265e5a51);        /* 19 */
        GG (b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
        GG (a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
        GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
        GG (c, d, a, b, x[15], S23, 0xd8a1e681);        /* 23 */
        GG (b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
        GG (a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
        GG (d, a, b, c, x[14], S22, 0xc33707d6);        /* 26 */
        GG (c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
        GG (b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
        GG (a, b, c, d, x[13], S21, 0xa9e3e905);        /* 29 */
        GG (d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
        GG (c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
        GG (b, c, d, a, x[12], S24, 0x8d2a4c8a);        /* 32 */

        /* Round 3 */
        HH (a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
        HH (d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
        HH (c, d, a, b, x[11], S33, 0x6d9d6122);        /* 35 */
        HH (b, c, d, a, x[14], S34, 0xfde5380c);        /* 36 */
        HH (a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
        HH (d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
        HH (c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
        HH (b, c, d, a, x[10], S34, 0xbebfbc70);        /* 40 */
        HH (a, b, c, d, x[13], S31, 0x289b7ec6);        /* 41 */
        HH (d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
        HH (c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
        HH (b, c, d, a, x[6], S34, 0x4881d05);  /* 44 */
        HH (a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
        HH (d, a, b, c, x[12], S32, 0xe6db99e5);        /* 46 */
        HH (c, d, a, b, x[15], S33, 0x1fa27cf8);        /* 47 */
        HH (b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */

        /* Round 4 */
        II (a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
        II (d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
        II (c, d, a, b, x[14], S43, 0xab9423a7);        /* 51 */
        II (b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
        II (a, b, c, d, x[12], S41, 0x655b59c3);        /* 53 */
        II (d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
        II (c, d, a, b, x[10], S43, 0xffeff47d);        /* 55 */
        II (b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
        II (a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
        II (d, a, b, c, x[15], S42, 0xfe2ce6e0);        /* 58 */
        II (c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
        II (b, c, d, a, x[13], S44, 0x4e0811a1);        /* 60 */
        II (a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
        II (d, a, b, c, x[11], S42, 0xbd3af235);        /* 62 */
        II (c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
        II (b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */

        state[0] += a;
        state[1] += b;
        state[2] += c;
        state[3] += d;

        /*
         * Zeroize sensitive information.
         */
        MD5_memset ((POINTER) x, 0, sizeof (x));
}

/* Encodes input (UINT4) into output (unsigned char). Assumes len is
  a multiple of 4.
 */
static void 
Encode (output, input, len)
unsigned char  *output;
UINT4          *input;
unsigned int    len;
{
        unsigned int    i,
                        j;

        for (i = 0, j = 0; j < len; i++, j += 4)
        {
                output[j] = (unsigned char) (input[i] & 0xff);
                output[j + 1] = (unsigned char) ((input[i] >> 8) & 0xff);
                output[j + 2] = (unsigned char) ((input[i] >> 16) & 0xff);
                output[j + 3] = (unsigned char) ((input[i] >> 24) & 0xff);
        }
}

/* Decodes input (unsigned char) into output (UINT4). Assumes len is
  a multiple of 4.
 */
static void 
Decode (output, input, len)
UINT4          *output;
unsigned char  *input;
unsigned int    len;
{
        unsigned int    i,
                        j;

        for (i = 0, j = 0; j < len; i++, j += 4)
                output[i] = ((UINT4) input[j]) | (((UINT4) input[j + 1]) << 8) |                        (((UINT4) input[j + 2]) << 16) | (((UINT4) input[j + 3]) << 24);
}

/* Note: Replace "for loop" with standard memcpy if possible.
 */

static void 
MD5_memcpy (output, input, len)
POINTER         output;
POINTER         input;
unsigned int    len;
{
        unsigned int    i;

        for (i = 0; i < len; i++)
                output[i] = input[i];
}

/* Note: Replace "for loop" with standard memset if possible.
 */
static void 
MD5_memset (output, value, len)
POINTER         output;
int             value;
unsigned int    len;
{
        unsigned int    i;

        for (i = 0; i < len; i++)
                ((char *) output)[i] = (char) value;
}

/**************** END OF MD5 ************/
